在 QML 中创建 C++ 导入类型的实例

在 QML 中创建 C++ 导入类型的实例

文件列表：

Project1.pro

QT += quick
CONFIG += c++11
CONFIG += declarative_debug
CONFIG += qml_debug

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += main.cpp 
    colormaker.cpp

RESOURCES += qml.qrc

# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =

# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH =

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

HEADERS += 
    colormaker.h

colormaker.h

#ifndef COLORMAKER_H
#define COLORMAKER_H

#include <QObject>
#include <QColor>

class ColorMaker : public QObject
{
    Q_OBJECT

    Q_ENUMS(GenerateAlgorithm)
    Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged)
    Q_PROPERTY(QColor timeColor READ timeColor)

public:
    explicit ColorMaker(QObject *parent = nullptr);
    ~ColorMaker();

    enum GenerateAlgorithm {
        RandomRGB,
        RandomRed,
        RandomGreen,
        RandomBlue,
        LinearIncrease
    };

    QColor color() const;
    void setColor(const QColor & color);
    QColor timeColor() const;

    Q_INVOKABLE GenerateAlgorithm algorithm() const;
    Q_INVOKABLE void setAlgorithm(GenerateAlgorithm algorithm);

signals:
    void colorChanged(const QColor & color);
    void currentTime(const QString &strTime);

public slots:
    void start();
    void stop();

protected:
    void timerEvent(QTimerEvent *ev);

private:
    GenerateAlgorithm m_algorithm;
    QColor m_currentColor;
    int m_nColorTimer;
};

#endif // COLORMAKER_H

colormaker.cpp

#include "colormaker.h"
#include <QTimerEvent>
#include <QDateTime>

ColorMaker::ColorMaker(QObject *parent)
    : QObject(parent),
      m_algorithm(RandomRGB),
      m_currentColor(Qt::black),
      m_nColorTimer(0)
{
    qsrand(QDateTime::currentDateTime().toTime_t());
}

ColorMaker::~ColorMaker()
{

}

QColor ColorMaker::color() const
{
    return m_currentColor;
}

void ColorMaker::setColor(const QColor &color)
{
    m_currentColor = color;
    emit colorChanged(m_currentColor);
}

QColor ColorMaker::timeColor() const
{
    QTime time = QTime::currentTime();
    int r = time.hour();
    int g = time.minute() * 2;
    int b = time.second() * 4;
    return QColor::fromRgb(r, g, b);
}

ColorMaker::GenerateAlgorithm ColorMaker::algorithm() const
{
    return m_algorithm;
}

void ColorMaker::setAlgorithm(ColorMaker::GenerateAlgorithm algorithm)
{
    m_algorithm = algorithm;
}

void ColorMaker::start()
{
    if (m_nColorTimer == 0) {
        m_nColorTimer = startTimer(1000);
    }
}

void ColorMaker::stop()
{
    if ( m_nColorTimer > 0 ) {
        killTimer(m_nColorTimer);
        m_nColorTimer = 0;
    }
}

void ColorMaker::timerEvent(QTimerEvent *ev)
{
    if ( ev->timerId() == m_nColorTimer ) {
        switch (m_algorithm) {
        case RandomRGB:
            m_currentColor.setRgb(qrand() % 255, qrand() % 255, qrand() % 255);
            break;
        case RandomRed:
            m_currentColor.setRed(qrand() % 255);
            break;
        case RandomGreen:
            m_currentColor.setGreen(qrand() % 255);
            break;
        case RandomBlue:
            m_currentColor.setBlue(qrand() % 255);
            break;
        case LinearIncrease:
            {
                int r = m_currentColor.red() + 10;
                int g = m_currentColor.green() + 10;
                int b = m_currentColor.blue() + 10;
                m_currentColor.setRgb(r % 255, g % 255, b % 255);
            }
            break;
        default:
            break;
        }

        emit colorChanged(m_currentColor);
        emit currentTime(QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss"));
    } else {
        QObject::timerEvent(ev);
    }
}

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include "colormaker.h"

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);

    qmlRegisterType<ColorMaker>("an.qt.ColorMaker", 1, 0, "ColorMaker");

    QQmlApplicationEngine engine;
    engine.load(QUrl(QLatin1String("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

main.qml

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3

import an.qt.ColorMaker 1.0

ApplicationWindow {
    visible: true;
     640;
    height: 480;
    title: qsTr("This is My Test");

    MainForm {
        anchors.fill: parent;
    }
}

MainForm.qml

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3

import an.qt.ColorMaker 1.0

Rectangle {
    id: mainForm;
     640;
    height: 480;

    Text {
        id: timeLabel;
        anchors.left: parent.left;
        anchors.leftMargin: 4;
        anchors.top: parent.top;
        anchors.topMargin: 4;
        font.pixelSize: 24;
    }

    ColorMaker {
        id: colorMaker;
        color: Qt.green;
    }

    Rectangle {
        id: colorRect;
        anchors.centerIn: parent;
         200;
        height: 200;
        color: "blue";
    }

    Button {
        id: start;
        text: "start";
        anchors.left: parent.left;
        anchors.leftMargin: 4;
        anchors.bottom: parent.bottom;
        anchors.bottomMargin: 4;
        onClicked: {
            colorMaker.start();
        }
    }

    Button {
        id: stop;
        text: "stop";
        anchors.left: start.right;
        anchors.leftMargin: 4;
        anchors.bottom: start.bottom;
        onClicked: {
            colorMaker.stop();
        }
    }

    function changeAlgorithm(button, algorithm)
    {
        switch(algorithm) {
        case 0:
            button.text = "RandomRGB";
            break;
        case 1:
            button.text = "RandomRed";
            break;
        case 2:
            button.text = "RandomGreen";
            break;
        case 3:
            button.text = "RandomBlue";
            break;
        case 4:
            button.text = "LinearIncrease";
            break;
        default:
            button.text = "null";
            break;
        }
    }

    Button {
        id: colorAlgorithm;
        text: "RandomRGB";
        anchors.left: stop.right;
        anchors.leftMargin: 4;
        anchors.bottom: start.bottom;
        onClicked: {
            var algorithm = (colorMaker.algorithm() + 1) % 5;
            changeAlgorithm(colorAlgorithm, algorithm);
            colorMaker.setAlgorithm(algorithm);
        }
    }

    Button {
        id: quit;
        text: "quit";
        anchors.left: colorAlgorithm.right;
        anchors.leftMargin: 4;
        anchors.bottom: start.bottom;
        onClicked: {
            Qt.quit();
        }
    }

    Component.onCompleted: {
        colorMaker.color = Qt.rgba(0, 180, 120, 1);
        colorMaker.setAlgorithm(ColorMaker.LinearIncrease);
        changeAlgorithm(colorAlgorithm, colorMaker.algorithm());
    }

    Connections {
        target: colorMaker;
        onCurrentTime: {
            timeLabel.text = strTime;
            timeLabel.color = colorMaker.timeColor;
        }
    }

    Connections {
        target: colorMaker;
        onColorChanged: {
            colorRect.color = color;
        }
    }
}

运行效果：